Stable herbicidal compositions comprising amine oxide and betaine

ABSTRACT

Provided is a herbicidal composition comprising high load aminophosphate or aminophosphonate salts, in particular high load glyphosate salts, wherein the composition comprises a surfactant mixture of at least an C 8 -C 10  amine oxide and a betaine surfactant. The composition has good low temperature stability (i.e., no crystal formation or phase separation) among other beneficial properties.

This application claims priority filed on 12 Jul. 2019 in INTERNATIONAL PROCEDURE with Nr CN2019/095673, the whole content of this application being incorporated herein by reference for all purposes.

FIELD OF THE INVENTION

The invention relates to stable agricultural herbicide compositions, comprising amine oxide and betaine.

BACKGROUND

Herbicidally active glyphosate compositions are known and are commercially available in the form of ammonium, isopropylamine and other salts. These herbicidal compositions are generally applied to weeds and unwanted vegetation in the form of an aqueous formulation containing a variety of adjuvants including for example wetting agents, surfactants, dispersants, anti-foam agents, humectants, and the like. The activity of the glyphosate composition may be improved considerably by the careful choice of additives.

Typically, there is a desire to have a higher glyphosate concentration, as the end-user (e.g., farmer) can modify the use concentration (amount of active applied to the field) by adjusting the dilution rate, and can avoid handling much product (the higher the concentration is, the lower the weight is for example).

Concentrated compositions can comprise a high amount of glyphosate, water, and at least one surfactant that can be useful as a formulation aid (dispersion, dissolution and/or stability of the glyphosate in water), and/or as a biological activator (for example increasing the efficacy the glyphosate, for example by encouraging wetting of a weed to be eliminated, or by encouraging penetration of the glyphosate into the weed). The relative amounts of glyphosate, surfactant(s) and optionally further ingredients may have also an effect onto the rheological properties of the formulation (for example viscosity, or ability to be spread). The rheological properties of the formulation as such or upon dilution are important for handling and spreading purpose.

European patent no. EP 1830652 B1 discloses use of betaine and amine oxide for glyphosate formulations containing up to 510 g/L of glyphosate actives.

Where the concentration of glyphosate is high, crystallization is often a significant problem. Crystallization can occur at different temperatures, at different glyphosate concentrations, or when diluting with water, but in particular is problematic at low temperatures. Crystallization is characterized by formation of small solid particles comprising glyphosate. These small particles can have the bad impact of filters clogging, nozzles clogging, creating unnecessary hazardous waste problems to dispose off the crystals, loss of activity (bioefficacy), and/or bad repartition of the active on the field. High viscosities of the formulations is also a problem as this can cause phase separation and/or difficulties for users in processing the formulations.

There is a need for new compositions that address at least one of the following: low temperature stability, lower cost, by using lower cost ingredients (the aminophosphate or aminophosphonate salts and/or the surfactants), better ecotoxic profile (especially lowering amounts of fatty ethoxyltes such as fatty amine ethoxyles), better viscosity profile, especially at lower temperature, and/or by avoiding crystallization, while keeping an acceptable efficacy or equivalent efficacy or even improving efficacy.

There is a continuing interest in agricultural pesticide compositions, more particularly agricultural fungicide compositions, which exhibit improved properties.

SUMMARY OF THE INVENTION

In one aspect, described herein is a composition, notably an aqueous herbicidal composition, comprising:

(i) at least two aminophosphate or aminophosphinate salts in a total amount of equal or greater than 540 g/L (ae); in particular at least two glyphosate salts in a total amount of equal or greater than 540 g/L (ae); (ii) an amine oxide surfactant of the formula:

R₁—N⁺R₂R₃—O⁻  (I)

wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or hydroxyalkyl; and (iii) a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; x is an integer of 1-3; wherein any two of the groups R₄-R₆ may optionally form a ring structure.

In some embodiments, the at least two aminophosphate or aminophosphinate salts, such as the at least two glyphosate salts, are present in a total amount of equal or greater than 540 g/L (ae), for instance equal or greater than 560 g/L (ae), for instance equal or greater than 600 g/L (ae).

In some embodiments, the amine oxide surfactant is an alkyl dimethyl amine oxide according to general formula:

R₇—N⁺(CH₃)₂—O⁻  (III)

wherein R₇ is a C₈-C₁₀, linear or branched, alkyl or hydroxyalkyl.

In some embodiments, R₄ and R₆ as defined in the general formula (II) (for betaine) is independently a C₁-C₄ alkyl, in particular methyl, x=1, and R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, in particular a C₈-C₁₆ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl.

In some embodiments, the composition further comprises a salt, in particular, a quaternary ammonium salt such as choline chloride.

In some embodiments, the composition further comprises a solvent. The solvent is present and comprises at least one of propylene glycol, glycerine or ethylene glycol.

In some embodiments, the composition is stable at a temperature of equal or less than 20° C., typically equal or less than 10° C., or equal or less than 5° C.

In another aspect, described herein are methods for regulating plant growth comprising contacting any aqueous herbicidal composition, as described herein, with a plant.

In another aspect, described is the use of any of the herbicidal compositions herein for spray applying to a plant.

DETAILED DESCRIPTION OF INVENTION

Throughout the description, including the claims, the term “comprising one” or “comprising a” should be understood as being synonymous with the term “comprising at least one”, unless otherwise specified. The terms “between” and “from . . . to . . . ” should be understood as being inclusive of the limits.

The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

It should be noted that in specifying any range of concentration, weight ratio or amount, any particular upper concentration, weight ratio or amount can be associated with any particular lower concentration, weight ratio or amount, respectively.

As used herein, the term “alkyl” means a saturated hydrocarbon radical, which may be straight, branched or cyclic, such as, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, t-butyl, pentyl, n-hexyl, cyclohexyl.

As used herein, the term “alkenyl” as a group or part of a group denotes an aliphatic hydrocarbon group containing at least one carbon-carbon double bond and which may be straight or branched. The group may contain a plurality of double bonds in the normal chain and the orientation about each is independently E or Z. Exemplary alkenyl groups include, but are not limited to, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl and nonenyl. The group may be a terminal group or a bridging group.

As used herein, the term “hydroxyalkyl” means an alkyl radical, which is substituted with a hydroxyl groups, such as hydroxymethyl, hydroxyethyl, hydroxypropyl, and hydroxydecyl.

As used herein, the terminology “(C_(n)-C_(m))” in reference to an organic group, wherein n and m are each integers, indicates that the group may contain from n carbon atoms to m carbon atoms per group.

As used herein, “liquid medium” means a medium that is in the liquid phase at a temperature of 25° C. and a pressure of one atmosphere. The liquid medium may be a non-aqueous liquid medium or an aqueous liquid medium.

As used herein the term “surfactant” means a compound that is capable of lowering the surface tension of water, more typically, a compound selected from one of five classes of compounds, that is, cationic surfactants, anionic surfactants, amphoteric surfactants, zwitterionic surfactants, and nonionic surfactants, as well as mixtures thereof.

In one embodiment, the liquid medium is an aqueous liquid medium. As used herein, the terminology “aqueous medium” means a single phase liquid medium that contains more than a trace amount of water, typically, based on 100 pbw of the aqueous medium, more than 0.1 pbw water. Suitable aqueous media more typically comprise, based on 100 pbw of the aqueous medium, greater than about 5 pbw water, even more typically greater than 10 pbw water. In one embodiment, the aqueous emulsion comprises, based on 100 pbw of the aqueous medium, greater than 40 pbw water, more typically, greater than 50 pbw water. The aqueous medium may, optionally, further comprise water soluble or water miscible components dissolved in the aqueous medium. The terminology “water miscible” as used herein means miscible in all proportions with water. Suitable water miscible organic liquids include, for example, (C₁-C₆)alcohols, such as methanol, ethanol, propanol, and (C₁-C₆)polyols, such as glycerol, ethylene glycol, propylene glycol, and diethylene glycol, The composition of the present invention may, optionally, further comprise one or more water insoluble or water immiscible components, such as a water immiscible organic liquid, wherein the combined aqueous medium and water insoluble or water immiscible components form a micro emulsion, or a multi-phase system such as, for example, an emulsion, a suspension or a suspo-emulsion, in which the aqueous medium is in the form of a discontinuous phase dispersed in a continuous phase of the water insoluble or water immiscible component, or, more typically, the water insoluble or water immiscible component is in the form of a discontinuous phase dispersed in a continuous phase of the aqueous medium.

The term “glyphosate composition” is used herein to mean a herbicidal composition comprising as active ingredient N-phosphonomethylglycine or a herbicidally acceptable salt thereof.

The amounts of the at least two aminophosphate or aminophosphonate salts, unless otherwise provided, are expressed as acid equivalents (ae). The amounts of surfactants or compositions of matter are amounts “as is”, as opposed to amounts as active matter, dry amounts, or the like, unless otherwise provided.

Glyphosate refers to N-(phosphonomethyl)glycine. Gluphosinate refers to 4-[hydroxy(methyl)phosphinoyl]-DL-homoalanine.

Aminophosphate or Aminophosphonate Salts

Aminophosphate or aminophosphonate salts are known by the one skilled in the art.

Preferred salts are glyphosate salts. Glyphosate refers to N-(phosphonomethyl)glycine. The glyphosate salts can be selected from:

-   -   sodium (Na) salts;     -   potassium (K) salts;     -   ammonium salts having N(R)₄ ⁺ cations wherein R groups,         identical or different, represent a hydrogen atom or a linear or         non linear, saturated or unsaturated C₁-C₆ hydrocarbon group         optionally substituted by a hydroxyl group, for example         isopropylamine salts;     -   sulphonium salts.

Ammonium salts that can in particular be cited include salts obtained from tertiary, secondary or primary amines such as triethylamine (TEA), isopropylamine (IPA), dimethylamine (DMA), monomethylamine (MMA), diamines such as ethylenediamine, or alkanolamines such as monoethanolamine (MEA). Trimethylsulphonium is notably a suitable sulphonium salt.

It has been found that bioefficacy of a glyphosate composition can be significantly improved by using specific combinations of low molecular weight non-amphiphilic cations. The present invention notably utilizes a glyphosate salt component comprising at least two cations, such as two, three or more cations.

Preferred glyphosate salts for the invention are a mixture of at least two salts selected from glyphosate potassium (K) salt, glyphosate sodium (Na) salt, isopropylamine (IPA) salt, monoethanolamine (MEA) salt, monomethylamine (MMA) salt, triethylamine (TEA), dimethylamine (DMA), trimethylsulphonium salt, and ammonium (NH₃) salt.

Advantageously, the glyphosate salts for the invention are a mixture of a glyphosate potassium (K) salt, and one or more selected from glyphosate sodium (Na) salt, isopropylamine (IPA) salt, monoethanolamine (MEA) salt, monomethylamine salt (MMA), trimethylsulphonium salt, and ammonium (NH₃) salt.

In some embodiments, the glyphosate salts comprise potassium and isopropylammonium cations and optionally other cations, and the mole ratio of isopropylammonium to potassium cations is less than 30:1 and greater than 1:30, more preferably less than 15:1 and greater than 1:15.

In some embodiments, the glyphosate salts comprise isopropylammonium and monoethanolammonium cations, and the mole ratio of monoethanolammonium to isopropylammonium cations is less than 30:1 and greater than 1:30, more preferably less than 15:1 and greater than 1:15.

In some embodiments, the glyphosate salts comprise potassium, monomethylamine and ammonium cations. In such cases, the mole ratio of monomethylamine cations to the sum of potassium, monomethylamine, and ammonium cations in the range 30:100 to 80:100.

The at least two glyphosate salts are present in a total amount of equal or greater than 540 g/L (ae), for instance equal or greater than 560 g/L (ae), for instance equal or greater than 600 g/L (ae).

Surfactants

The composition of the invention comprises, in addition to the high load herbicidal active ingredients as described above, a surfactant system comprising at least an amide oxide and a betaine surfactants.

In one embodiment, the composition comprises a surfactant mixture of at least:

-   -   an amine oxide surfactant of the formula:

R₁—N⁺R₂R₃—O⁻  (I)

-   -   wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or         hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or         hydroxyalkyl; and     -   a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

-   -   wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or         hydroxyalkenyl;     -   R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or         a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   x is an integer of 1-3;     -   wherein any two of the groups R₄-R₆ may optionally form a ring         structure.

It is appreciated that said amine oxide surfactant is a C₈-C₁₀ amine oxide, which in context of the present invention refers to an amine oxide which contains C₈-C₁₀ alkyl chain only at the R₁ position or an amine oxide which contains substantially C₈-C₁₀ alkyl chain at the R₁ position. “Containing substantially C₈-C₁₀ alkyl chain” means it contains at least 90% C₈-C₁₀ alkyl chain based on the total alkyl chain for the R₁ position.

In one embodiment, the composition comprises a surfactant mixture of at least:

—R₇—N⁺(CH₃)₂—O⁻  (III)

wherein R₇ is a C₈-C₁₀, linear or branched, alkyl or hydroxyalkyl; and

-   -   a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

-   -   wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or         hydroxyalkenyl;     -   R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or         a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   x is an integer of 1-3;     -   wherein any two of the groups R₄-R₆ may optionally form a ring         structure.

In one embodiment, the composition comprises a surfactant mixture of at least:

-   -   an amine oxide surfactant of the formula:

R₁—N⁺R₂R₃—O⁻  (I)

-   -   wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or         hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or         hydroxyalkyl; and     -   a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

-   -   wherein R₄ and R₆ is independently a C₁-C₄ alkyl, in particular         methyl;     -   x=1; and     -   R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl,         in particular a C₈-C₁₆ alkyl, alkenyl, hydroxyalkyl or         hydroxyalkenyl.

In one embodiment, the composition comprises a surfactant mixture of at least:

—R₇—N⁺(CH₃)₂—O⁻  (III)

-   -   wherein R₇ is a C₈-C₁₀, linear or branched, alkyl or         hydroxyalkyl; and     -   a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

-   -   wherein R₄ and R₆ is independently a C₁-C₄ alkyl, in particular         methyl;     -   x=1; and     -   R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl,         in particular a C₈-C₁₆ alkyl, alkenyl, hydroxyalkyl or         hydroxyalkenyl.

Said amine oxide according to general formula (I), for example, is octyl dimethyl amine oxide, decyl dimethyl amine oxide.

Said betaine according the general formula (II), for example, includes and is not limited to: decyl dimethyl betaine, coco dimethyl betaine, myristyl dimethyl betaine, palmityl dimethyl betaine, lauryl dimethyl betaine, cetyl dimethyl betaine, stearyl dimethyl betaine. In particular, the betaine suitable for the invention is an alkyldimethyl betaine, such as lauryl dimethyl betaine. The betaine can be provided as a betaine surfactant composition which comprises water, the betaine and optionally a salt, such as potassium or sodium based salt of chloride or hydroxide.

In some embodiments, the amine oxide surfactant is present in an amount ranging from about 0.1 wt % to about 20 wt %, based on the total weight of the aqueous herbicidal composition, for instance from about 0.1 wt % to about 15 wt %, for instance from about 0.1 wt % to about 10 wt %.

In some embodiments, the betaine surfactant is present in an amount ranging from about 0.1 wt % to about 20 wt %, based on the total weight of the aqueous herbicidal composition, for instance from about 0.1 wt % to about 15 wt %, for instance from about 0.1 wt % to about 10 wt %.

In some embodiments, weight ratio of the amine oxide surfactant and the betaine surfactant is in the range of from 30/70 to 70/30, for instance from 40/60 to 70/30, for instance from 40/60 to 60/40.

The herbicidal compositions as described herein, incorporating high load of active ingredients, are characterized by at least one of the following properties: low temperature stability, bioefficacy, and low viscosity. The surfactant mixtures as described herein can protect certain concentrated water soluble liquid herbicide formulations from instability at low storage temperatures when compared to the same formulations prepared using longer chain amine oxides. The surfactant mixtures as described herein can protect certain concentrated water soluble liquid herbicide formulations from instability at low storage temperatures when compared to the same formulations containing a sole surfactant, such as amine oxide alone or betaine alone.

Accordingly, the present invention provides a method for enhancing the storage stability of an aqueous herbicidal composition comprising at least two aminophosphate or aminophosphinate salts in a total amount of equal or greater than 540 g/L (ae), wherein the method comprises the step of adding to the composition a surfactant mixture of at least:

-   -   an amine oxide surfactant of the formula:

R₁—N⁺R₂R₃—O⁻  (I)

-   -   wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or         hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or         hydroxyalkyl; and     -   a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

-   -   wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or         hydroxyalkenyl;     -   R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or         a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   x is an integer of 1-3;     -   wherein any two of the groups R₄-R₆ may optionally form a ring         structure.

In particular, the present invention provides a method for enhancing the storage stability of an aqueous herbicidal composition comprising at least two glyphosate salts in a total amount of equal or greater than 540 g/L (ae), wherein the method comprises the step of adding to the composition a surfactant mixture of at least:

-   -   an amine oxide surfactant of the formula:

R₁—N⁺R₂R₃—O⁻  (I)

-   -   wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or         hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or         hydroxyalkyl; and     -   a betaine surfactant of the formula:

R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II)

-   -   wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or         hydroxyalkenyl;     -   R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or         a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;     -   x is an integer of 1-3;     -   wherein any two of the groups R₄-R₆ may optionally form a ring         structure.

The subject surfactant mixtures may be provided as in-package formulation adjuvants, which allow large-scale production of highly concentrated water soluble herbicide salt formulations, such as those containing the mixture of at least two salts of N-phosphonomethylglycine (commonly called glyphosate acid).

In some embodiments, the composition is stable at a temperature of equal or less than 20° C., typically equal or less than 10° C., or equal or less than 5° C. In this context, stability means minimal or no crystal formation nor phase separation at said low temperature. In another embodiment, stability means reduced formulation viscosity at said low temperature.

In some embodiments, the herbicidal compositions as described herein, optionally, contain a salt or a mixture of salts. The salt suitable for the present invention includes and is not limited to: quaternary ammonium salt such as choline chloride, ammonium sulfate, EDTA sodium salt, oxalate. In particular, the salt is a quaternary ammonium salt, preferably choline chloride.

In some embodiments, the herbicidal compositions as described herein, optionally, contain a solvent or blend of solvents. In one embodiment, the solvent is a polar solvent. In another embodiment, the solvent is water-miscible. The solvent includes, but is not limited to, one or a mixture of: a water-miscible glycol ether, a water-miscible polyhydric alcohol (e.g., glycerine or propylene glycol) ether, a water-miscible alcohol, a water-miscible ketone, a water-miscible aldehyde, a water-miscible acetate.

In some embodiments, the solvent is present in the herbicidal composition and comprises at least one of propylene glycol, glycerine or ethylene glycol.

Other solvents (or solvent blends include at least one of the following) include: N-methyl-pyrrolidone (NMP, can be further identified for example with CAS number 872-50-4), diester solvents, propylene carbonate, acetophenone, ethylene glycol butyl ether, diethylene glycol butyl ether, methoxy methyl butanol, propylene glycol methyl ether, dipropylene glycol methyl ether, gamma-butyrolactone, dimethyl formamide (DMF), furfuryl alcohol, tetrahydrofuryl alcohol, neopentyl glycol, hexadiols, hexylene glycol, glycol ether amines, ethylene glycol monoacetate.

In another aspect, described herein are methods for regulating plant growth comprising contacting any aqueous herbicidal composition, as described herein, with a plant.

In another aspect, described is the use of any of the herbicidal compositions herein for spray applying to a plant.

Further Additional Components

The herbicidal composition as described herein can, in other embodiments, comprise additional components such as: additional surfactants different from said C₈-C₁₀ amine oxide and betaine surfactants, anti-foaming agents, solvents (e.g., water miscible solvent, polar solvents, and the like), deposition control agents such as anti-rebound or anti-drift agents. In one embodiment, such additional components are optionally added after the initial formulation step. This additional surfactant, in some embodiments, can provide further advantages or synergies in term of costs, and/or bioefficacy, and/or rheology management, and/or environment concerns.

Some non-limiting examples of the additional surfactants include at least one of: an ethoxylated fatty amine; a fatty amine; an ether carboxylate; an acid or non acid mono- and di-ester phosphate, optionally polyalkoxylated; an alkylmonoglycoside or alkylpolyglycoside, advantageously octylglycoside, an octylpolyclycoside, decylglycoside, a decylpolyglycoside.

In a particular embodiment the composition is substantially free (less than 10% by weight of the total composition, preferably less than 1%, preferably none) of a humectant selected from polyhydric alcohols, polysaccharide humectants, and mixtures thereof.

The compositions of the invention can be prepared by mixing their different constituents with moderate stirring, at a temperature in the range 15° C. to 60° C. In one embodiment, the temperature is ambient temperature (15-30° C.). The surfactant, in one embodiment, is added after the other components have been added and mixed. Alternatively the surfactant or a part thereof is added during neutralization of the aminophophate or aminophosphonate. The remaining components can be added afterwards.

The herbicidal composition of the invention can be thus used to treat plants, normally after diluting with water. The diluted composition can be applied onto a field by any appropriate mean. The dilution, and the application onto the field, can be for example such that the total amount of the at least two aminophosphate or amoniphosphonate salts, is of from 540 g acid equivalent/ha to 1500 g acid equivalent/ha, for instance from 560 to 1200 g/ha, for instance from 600 to 1200 g/ha.

Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

Examples

Materials

-   -   Geronol® CF/AS 46HL is C₁₂₋₁₄ dimethyl betaine from Solvay;     -   Mackamine® C₈ is C₈ dimethyl amine oxide from Solvay;     -   Mackamine® C₁₀ is C₁₀ dimethyl amine oxide from Solvay;     -   Geronol® CF/K is C₁₂-C₁₄ dimethyl amine oxide from Solvay;

Glyphosate formulations containing MMA/K/NH₄ salts were prepared by using the steps below:

-   -   a) a glyphosate salt mixture containing MMA/K/NH₄ salts was         prepared by firstly making a MMA/KOH/NH₃ bases at a molar ratio         of 70/25/5 or 60/35/5.     -   b) Add the base mixture to the vessel.     -   c) Slowly charge reaction vessel the Glyphosate acid with         continuous stirring, and cool the mixture if temperature         succeeds 40° C.     -   d) check the pH (7% w/w) solution to confirm that neutralization         is complete, if not add extra Base Mixture.     -   e) add Surfactant and mix in.     -   f) add remaining water subtracting any extra addition for the pH         adjustment.     -   g) the final composition had a glyphosate concentration based on         glyphosate acid equivalent indicated in the table expressed in         grams of glyphosate acid equivalent per liter of composition (g         ae/L Glyphosate).

Glyphosate formulations containing K/IPA salts were prepared by using the procedures below:

-   -   a) a glyphosate salt mixture containing K/IPA salts was prepared         by firstly making a MIPA and KOH base mixture at a molar ratio         of 1.345:1.     -   b) Add 80% of the water to the vessel.     -   c) charge reaction vessel with 50% of the Glyphosate acid to         form the slurry and activate the mixing process.     -   d) add 50% of the Base Mixture solution, mix for approximately 1         hour. Cool mixture if temperature succeeds 60° C.     -   e) add remaining 50% of the glyphosate acid.     -   f) add remaining 50% of the Base Mixture and mix until         homogenous     -   g) check the pH (7% w/w) solution to confirm that neutralization         is complete, if not add extra Base Mixture.     -   h) add Surfactant when temperature drops to 40° C. or below and         mix in.     -   i) add remaining water subtracting any extra addition for the pH         adjustment.     -   j) the final composition had a glyphosate concentration based on         glyphosate acid equivalent indicated in the table expressed in         grams of glyphosate acid equivalent per liter of composition (g         ae/L Glyphosate).

Viscosity profiles were tested for stability, including low temperature stability. The viscosities (cP) was measured by using an RVT Spindle 2, at a speed of 20 rpm, at various temperatures.

Results are shown in Tables 1 to 3 below. In these tables, “S” refers to samples and “CS” refers to Comparative Samples.

TABLE 1 Viscosity Temperature Profile Viscosity (cP) 5° 10° 15° 20° 600 g ae/L Formulations C. C. C. C. S1 MMA/K/NH₄ (70/25/5, 600 g/L) 310 220 170 130 Geronol ® CF/AS 46HL (75 g/L) Mackamine ® C₈ (75 g/L) S2 MMA/K/NH₄ (70/25/5, 600 g/L) 2125 1500 975 675 Geronol ® CF/AS 46HL (75 g/L) Mackamine ® C₁₀ (75 g/L) CS1 MMA/K/NH₄ (70/25/5, 600 g/L) phase separation Geronol ® CF/AS 46HL (75 g/L) Geronol ® CF/K (75 g/L) CS2 MMA/K/NH₄ (70/25/5, 600 g/L) phase separation Geronol ® CF/AS 46HL (150 g/L)

TABLE 2 Viscosity Temperature Profile Viscosity (cP) 5° 10° 15° 20° 600 g ae/L Formulations C. C. C. C. S3 MMA/K/NH₄ (60/35/5, 600 g/L) 250 175 125 100 Geronol ® CF/AS 46HL (75 g/L) Mackamine ® C₈ (75 g/L) S4 MMA/K/NH₄ (60/35/5, 600 g/L) 2075 1375 900 625 Geronol ® CF/AS 46HL (75 g/L) Mackamine ® C₁₀ (75 g/L) CS3 MMA/K/NH₄ (60/35/5, 600 g/L) phase separation Geronol ® CF/AS 46HL (75 g/L) Geronol ® CF/K (75 g/L) CS4 MMA/K/NH₄ (60/35/5, 600 g/L) phase separation Geronol ® CF/AS 46HL (150 g/L)

TABLE 3 Viscosity Temperature Profile Viscosity (cP) 5° 10° 15° 20° 540 g ae/L Formulations C. C. C. C. S5 K/IPA (57/43, 540 g/L) 275 200 135 100 Geronol ® CF/AS 46HL (67.5 g/L) Mackamine ® C₈ (67.5 g/L) S6 K/IPA (57/43, 540 g/L) 425 260 175 135 Geronol ® CF/AS 46HL (67.5 g/L) Mackamine ® C10 (67.5 g/L) CS5 K/IPA (57/43, 540 g/L) 3200 1650 675 410 Geronol ® CF/AS 46HL (67.5 g/L) Geronol ® CF/K (67.5 g/L) CS6 K/IPA (57/43, 540 g/L) 610 410 290 210 Mackamine ® C₈ (135 g/L) CS7 K/IPA (57/43, 540 g/L) crystallization Mackamine ® C₁₀ (135 g/L) CS8 K/IPA (57/43, 540 g/L) 530 370 250 180 Geronol ® CF/AS 46HL (135 g/L)

It was shown that the surfactant mixtures according to the invention could make the high load glyphosate formulations stable, even at low temperatures. In contrast, the mixture of betaine and amine oxide having longer chains led to poor stability in 600 g ae/L formulations, and very high viscosity in the 540 g ae/L formulations which is not favorable. Also, the betaine surfactant alone or the amine oxide surfactant alone led to high viscosities which is unfavorable.

Bioefficacy Evaluation

A greenhouse bioassay used annual ryegrass and variegated thistle to assess the effect of 2 high-load glyphosate (≈600 g/L) formulations. Each formulation was applied at either 90, 180 or 360 g ai/ha. A % control and fresh weight assessment were completed at 10 and 14 days after application (DAA) respectively.

Annual ryegrass and variegated thistle were sown in 10 cm diameter pots (0.70 L) filled with potting mix. Seedings were grown in a greenhouse where temperature ranged between 10-35° C.

Herbicide treatments were applied using a DeVries Generation III Research track-sprayer. Spray solutions were prepared by adding water to tared 600 ml PET bottles to the designated mass (±1 g) (AND electronic balance, GF-6000±0.1 g) followed by the formulations. The PET bottles were capped, shaken and allowed to stand for 5 minutes before spray application.

A visual assessment of % control was completed at 10 DAA and a fresh weight (g) assessment was completed at 14 DAA. A visual rating scale was established by selecting plants with varying levels of herbicide damage and scoring in 10% increments with a 0% control being no symptoms and 100% being plant mortality. Seedlings treated with each formulation (90, 180 and 360 g ai/ha) were photographed at 14 DAA just before the fresh weight. For the fresh weight assessment, seedlings were harvested by cutting foliage at the stem base immediately prior to weighing (AND GF-300±0.01 g electronic balance).

Data was analyzed using ANOVA. 5% least significant differences (LSD) were calculated for the mean of each treatment. For visual assessments, the greatest herbicidal effect is denoted with alpha code “a” when significantly different to other treatments, which are coded “b”, “c”, “d” etc. with decreasing herbicidal effect. Alpha codes were reversed for fresh weight analysis.

TABLE 4 bioefficacy evaluation results for Annual Ryegrass visual assessment of % fresh weight assessment Treatment control at 10 DAA at 14 DAA with 90 g 180 g 360 g 90 g 180 g 360 g formulation ai/ha ai/ha ai/ha ai/ha ai/ha ai/ha S1 30 g 60 cd 71 ab 2.50 c 0.61 e 0.17 e S3 49 de 74 ab 84 a 1.35 de 0.29 e 0.11 e Donaghys 43 ef 67 bc 80 a 2.03 cd 0.66 e 0.15 e Grunt 600 LSD 8.8 0.836

TABLE 5 bioefficacy evaluation results for Variegated thistle visual assessment of % fresh weight assessment Treatment control at10 DAA at14 DAA with 90 g 180 g 360 g 90 g 180 g 360 g formulation ai/ha ai/ha ai/ha ai/ha ai/ha ai/ha S1 43 f 63 e 89 ab 11.43 b 4.32 ef 0.41 h S3 40 f 59 e 93 ab 8.87 c 5.77 de 0.77 gh Donaghys 49 f 79 c 99 a 7.19 cd 1.23 gh 0.40 h Grunt 600 LSD 7.6 1.87

As shown in tables 4 and 5, the aqueous herbicidal composition of the present invention showed favorable herbicidal bioefficacy. 

1. An aqueous herbicidal composition comprising: at least two aminophosphate or aminophosphinate salts in a total amount of equal or greater than 540 g/L (ae); an amine oxide surfactant of the formula: R₁—N⁺R₂R₃—O⁻  (I) wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or hydroxyalkyl; and a betaine surfactant of the formula: R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II) wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; x is an integer of 1-3; wherein any two of the groups R₄-R₆ may optionally form a ring structure.
 2. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate salts.
 3. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are present at equal or greater than 560 g/L (ae).
 4. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are present at equal or greater than 600 g/L (ae).
 5. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are selected from the group consisting of glyphosate potassium (K) salt, glyphosate sodium (Na) salt, glyphosate isopropylamine (IPA) salt, glyphosate monoethanolamine (MEA) salt, glyphosate monomethylamine (MMA) salt, glyphosate triethylamine (TEA) salt, glyphosate dimethylamine (DMA) salt, glyphosate trimethylsulphonium salt, and glyphosate ammonium (NH₃) salt.
 6. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate potassium salt and glyphosate isopropylammonium salt.
 7. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate potassium salt and glyphosate ammonium salt.
 8. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate isopropylammonium salt and glyphosate monoethanolammonium salt.
 9. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate isopropylammonium salt and glyphosate ammonium salt.
 10. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate potassium salt, glyphosate monomethylamine salt and glyphosate ammonium salt.
 11. The aqueous herbicidal composition of claim 1, wherein said aminophosphate or aminophosphinate salts are glyphosate monomethylamine salt, glyphosate isopropylammonium salt and glyphosate ammonium salt.
 12. The aqueous herbicidal composition of claim 1, wherein said amine oxide surfactant is according to: —R₇—N⁺(CH₃)₂—O⁻  (III) wherein R₇ is a C₈-C₁₀, linear or branched, alkyl or hydroxyalkyl.
 13. The aqueous herbicidal composition of claim 1, wherein said betaine surfactant is according to the general formula: R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II) wherein R₄ and R₆ is independently a C₁-C₄ alkyl; x=1; R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl.
 14. The aqueous herbicidal composition of claim 1, wherein said amine oxide surfactant is octyl dimethyl amine oxide or decyl dimethyl amine oxide.
 15. The aqueous herbicidal composition of claim 1, wherein weight ratio of said amine oxide surfactant and said betaine surfactant is in the range of from 30/70 to 70/30.
 16. The aqueous herbicidal composition of claim 1, wherein said amine oxide surfactant is present in an amount of from 0.1 wt % to 10 wt %, based on the total weight of the aqueous herbicidal composition.
 17. The aqueous herbicidal composition of claim 1, wherein said betaine surfactant is present in an amount of from 0.1 wt % to 10 wt %, based on the total weight of the aqueous herbicidal composition.
 18. The aqueous herbicidal composition of claim 1, wherein the composition further comprises choline chloride.
 19. A method for regulating plant growth comprising contacting an aqueous herbicidal composition according to claim 1, with a plant.
 20. (canceled)
 21. A method for enhancing the storage stability of an aqueous herbicidal composition comprising at least two glyphosate salts in a total amount of equal or greater than 540 g/L (ae), wherein the method comprises the step of adding to the composition a surfactant mixture of at least: an amine oxide surfactant of the formula: R₁—N⁺R₂R₃—O⁻  (I) wherein R₁ is a C₈-C₁₀, linear or branched, alkyl or hydroxyalkyl; R₂ and R₃ is independently a C₁-C₄ alkyl or hydroxyalkyl; and a betaine surfactant of the formula: R₄R₅R₆N⁺(CH₂)_(x)C(O)O⁻  (II) wherein R₄ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; R₅ is a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; R₆ is a C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, or a C₆-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; x is an integer of 1-3; wherein any two of the groups R₄-R₆ may optionally form a ring structure. 